Rockford's board voted unanimously to carry out 17 of the discipline cases, which included 13 expulsions and four 10-day suspensions.
One board member pushed to have two of the expulsion decisions held until the next board meeting because of errors in the documentation.
The student acts, which all happened between late August and mid-September, ranged from fighting to group violence. They also included possession of handguns and marijuana.
The board spent about an hour in closed session discussing and ruling on the discipline cases. Members say they made the right decision.
"When students bring guns to school, when they sell drugs in our school, we have zero tolerance for that kind of thing and we do want to communicate a message that we are not going to jeopardize the safety of the students in the schools," board member Mike Williams said.